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All Flash Or Tiered Storage?

Which storage technology is best for your Oracle based app?

There’s much debate on which storage technology (i.e. flash storage or tiered storage) will perform best for an Oracle application.

Many Oracle gurus say the standard block size for OLTP apps should be small, around 4KB. That being the case, AFA products should excel for Oracle workloads of this size. If only life could mimic the spec sheet. But alas, it does not.

In practice, application workloads sometimes follow a very different path. We recently worked on an Oracle workload project where the average block size was 110KB. This surprised many of the all flash array vendors who generated latencies in the region of 7 or 8 milliseconds instead of 1-2ms.

This is important.

A major reason for migrating from spinning disk or tiered storage to AFA is to achieve low latency. If you are instead hitting 7 or 8ms latency for some of your workloads with an AFA, it highlights the need to test before you go out and spend time and money on AFAs for your workloads.

We observed that some Tiered Storage out-performed certain All Flash Array systems for larger block size based workloads. Customers today often think by simply throwing more capacity or cache solves every performance issue. And if you factor in cost, the reason to move to AFA becomes far less compelling… for some workloads. This is why people need to check out what their ACTUAL workload characteristics are, then model them in different scenarios to make more intelligent deployment decisions.